Liquid atomizer



A ril 13, 1965 w. L. DRAYER LIQUID ATOMIZER Filed May 28, 1963 INVENTOR. dz/421x22 599/45 6? flTTQFA/EI United States Patent Ofifice 3,1783% Patented Apr. 13, 1965 3,178,115 LIQUID ATOMIZER William L. Drayer, Warren, Mich, assiguor to General Motors (Jorporation, Detroit, Mich, a corporation of Delaware Filed May 2S, 1963, Ser. No. 283360 3 (Ilaizns. (Eli. 239-102) This invention relates to an atomizer and more particularly to an apparatus that utilizes vibratory energy for 1 atomizing liquid.

The use of vibrations for purposes of achieving atomization of liquid is not new and one example of an apparatus of this sort can be seen in co-pending patent application Serial No. 177,601, filed March 5, 1962, now Patent No. 3,123,302, in the name of William L. Drayer and assigned to the assignee of this invention. The atomizer shown in that application includes an elongated tube fixed at one end within a housing that accommdates an air driven vibrator. The vibrator has a ring-type mass adapted to be driven about the tube so as to cause gyration of the free end of the tube at a frequency which produces suflicient centrifugal force to atomize liquid at the tubes free end. This particular device has been used for atomizing non-viscous liquids such as gasoline and water with extremely good results, however, some difliculty has been found in realizing fine mist-like droplets in cases where a viscous liquid such as paint or oil is to be atomized. Moreover, the volume of liquid passing through the tube has been found to be critical and when the liquid flow rate is increased to meet certain requirements, at times this causes a dampening of the vibrations with resultant decrease in the amount of centrifugal force necessary for good atomization.

Accordingly, a principal object of this invention is to provide a vibratory atomizer having a construction which permits standing-wave gyratory movement of a nozzle at a frequency which generates sufiicient centrifugal force to atomize viscous liquids being delivered to the nozzle at a high flow rate.

Another object of this invention is to provide a vibratory atomizer in which the nozzle is subjected to gyratorytype movement and includes means that mechanically form the liquid into a thin film which may be readily atomized by the centrifugal force being generated by the gyrating nozzle.

The above and other objects are accomplished by an atomizer having an elongated fiexural member supported at its nodal points by adjustable collars. A nozzle is provided at one end of the fiexural member while the opposite end houses an air driven vibrator which is adapted to generate a rotating force vector at a frequency which sets up a gyratory standing-wave movement of the fiexural member. The nozzle is located at an antinode point of the flexural member and has a roller mounted therein for orbital movement with respect to the nozzle. Thus, as the nozzle is subjected to gyratory movement the roller compresses the liquid into a thin film which is subsequently atomized by centrifugal force.

A more complete understanding of this invention can be obtained from the following detailed description when taken in conjunction with the drawings in which:

FIGURE 1 is an elevation view partly in section, showing an atomizer made in accordance with the invention,

FIGURE 2 is a view of the vibrator taken on line 22 of FIGURE 1,

FIGURE 3 is a view taken on line 3-3 of FIGURE 1,

FIGURE 4 is an enlarged view showing the detail construction of the nozzle taken on line 4-4 of FIGURE 1, and

FIGURE 5 shows the atomizer of FIGURE 1 with a modified nozzle.

Referring to FIGURE 1, an atomizer made in accordance with the invention is shown comprising a cylindri' cally shaped bar or lleXural member 12 which at one end supports an air driven vibrator 14. Compressed air is directed to the vibrator through a conduit 16 which communicates with a tank 18 of pressurized air and includes a valve 20 for controlling the air supply. The opposite end of the flexural member is provided with a nozzle 22 which receives liquid from a reservoir 24 via a conduit 26. As in the case of the air supply for the vibrator, a valve 28 is provided in the conduit 26 for regulating the amount of liquid being directed to the nozzle.

The vibrator end of the fiexural member is concentrically positioned within a tubular base housing 3% formed with a radially extending annular flange 32. An axially projecting rod 34 is secured at one end to the flange and supports a pair of collars 36 and 38 which in turn support the fiexural member at the nodal points thereof. As seen in FIGURE 3, each collar is provided with a set screw 46 that permits the collar to be adjustably positioned along the rod so that the fiexural member may be supported at its nodal points during standing-wave vibration.

The vibrator 14 comprises a ring-shaped track 42 that freely supports a cylindrical mass or roller 4-4. As best seen in FIGURE 2, the track is provided with a plurality of nozzles 46 which are so located so as to direct a stream of air tangentially against the periphery of the mass to drive it in an orbiting manner about the track. Thus, as the roller is driven around the track it causes a centrifugal force to act against the latter so as to, in etIect, produce a rotating force vector. A vibrator of this sort is capable of operating at high frequencies when the diameter of the roller is greater than one-half the diameter of the track. When such is the case, a frequency step-up occurs which causes a number of force impulses greater than one to be generated for each complete revolution of the roller about its axis. For a more complete understanding of the principle of operation of this vibrator, reference is made to the patent to Svenson 2,194,410.

The nozzle 22 is a significant feature of this invention, and comprises a plug like body portion 48 one end of which is adapted to be press fitted into a bore St formed in the fieXural member. The rear end of the bore forms a chamber 52 for liquid which communicates with an axial passage 54 that leads to the conduit 26. In addition, the chamber 52 communicates with a passage 56 in the nozzle portion 48 that opens into a chamber 58 having the shape of a frustum. Rotatably mounted in the cham ber 58 on pin 60 is a plastic roller 62 also having the configuration of a frustum with an outer diameter slightly less than the accommodating chamber. Thus, as seen in FIGURE 4, an arcuate gap is formed between a portion of the periphery of the roller and the inner wall of chamber 53. Moreover, it should be noted that the roller has a centrally formed aperture 64 which is of a diameter greater than the diameter of the pin so that the latter does not interfere with the function of the roller which will be explained together with the operation of the atomizer.

To operate this atomizer, compressed air is directed to the vibrator 14 by opening the valve 26. As seen in FIGURE 2, the air enters the vibrator at a tangential attitude and is directed by the nozzles 46 against the mass 44 to propel the latter in an orbital fashion about the track 42. As alluded to earlier, the orbiting mass generates a rotating force vector normal to the longitudinal axis of the flexural member 12 and causes gyratory movement thereof. For most efiicient operation, the mass is driven at a frequency equal to the reasonant frequency or" the fiexural member so as to develop a gyrato-ry standing-wave in the flexural member. During standing-wave motion the flexural member will bend as seen by the de flection curves A and B in FIGURE 1, and it should be noted that at the points of intersection of these curves there is no bending or movement of the flexural member and, accordingly, these points are termed the nodal points. The points of maximum bending in the region of the vibrator and nozzle are termed antinode points. collars 36 and 38 are located at the nodal points and, in addition, the liquid conduit 26 is connected to the flexural member at a nodal point so as not to impart any movement to the conduit.

As the flexuralmember is being gyrated at its resonant frequency, liquid under the control of valve 28 is directed to the nozzle 22. Inasmuch as the nozzle is located at an antinode point of the flexural member, it experiences a gyratory movement which causes the roller 62 to move along the inner wall of the chamber 58 in an orbiting fashion somewhat similar to that followed by the mass in the vibrator. As the roller 62 moves around the chamber, it mechanically squeezes or compresses the liquid into a thin arcuate film which is then atomized by the centrifugal force developed by the gyrating nozzle. It has been found that by augmenting the gyrating movement ofthe nozzle with the compressing of the fluid extremely fine atomization can be obtained even of the most viscous liquids.

The modified nozzle 22' shown in FIGURE 5 can be substituted for the nozzle of FIGURE 1 and also obtain good atomization. In instances where the nozzle 22' is utilized, the driving system comprising the vibrator 14 and flexural member 12 should be matched to the resonant frequency of the nozzle. As a result, when either nozzle 22' or 22 are used, an increase in the liquid flow rate does not affect the operating efficiency of the apparatus and excellent atomization can be obtained inasmuch as the mass of the flexural member is comparatively large with respect to the mass of the nozzle and liquid. For optimum atomization the vibrator should be operated at a frequency not less than 100 cycles per second and preferably in the resonant frequency range of the flexural member in both instances.

Various changes and modifications within the spirit of the invention are contemplated by the inventor, and there fore he does not wish to be limited except by the scope of the following claims.

What is claimed is:

1. An apparatus for atomizing liquid comprising a base. member, an elongated flexural member, means connected. to said base for supporting said flexural member, a nozzle formed at one end of said flexural member, means for supplying liquid to said nozzle, a vibrator connected to said flexural member, means for driving said vibrator to cause a gyratory movement of said flexural member and nozzle, said nozzle having a chamber communicating with said liquid supply means, a pin located in said chamber with its axis parallel to the longitudinal axis of the flexural member, said chamber being circular in cross-section, a roller having a diameter less than said chamber being supported in the latter by said pin for orbital movement thereabout and engaging a portion of the inner wall of said chamber, said roller adapted to follow an orbital path about said chamber as a result of said gyratory The support 7 movement and to engage different portions of said chamher to compress said liquid into a thin arcuate film so as to permit the centrifugal force generated by the gyratory movement of the nozzle to atomize the liquid film.

2. An apparatus for atomizing liquid comprising a base member, an elongated flexural member, means connected to said base for supporting said flexural member, a nozzle formed at one end of said flexural member, means for supplying liquid to said nozzle, a vibrator connected to said flexural member, means for driving said vibrator to cause a resonant standing wave gyratory movement of said flexural member and nozzle, said nozzle having a chamber communicating with said liquid supply means, a pin fixed to said nozzle and located in said chamber with its axis parallel to the longitudinal axis of the flexural member, said chamber being circular in cross section, a roller having a diameter less than said chamber being supported in the latter by said pin for orbital movement thcreabout and engaging a portion of the inner wall of said chamber, said roller adapted to'follow an orbital path about said chamber as a result of said gyratory movement and to engage different portions of said chamber to compress said liquid into a thin arcuate film so as to permit the centrifugal force generated by the gyratory movement of the nozzle to atomize the liquid film.

3. An apparatus for atomizing liquid comprising a base member, an elongated flexural member, means connected to said base for supporting said flexural member, a nozzle formed at one end of said flexural member, means for supplying liquid to said nozzle, a vibrator connected to said flexural member at the other end thereof, means for driving said vibrator to cause a gyratory movement of said flexural member and nozzle, said nozzle terminating with a frustum-shaped chamber, a feeder passage formed in the nozzle and communicating with said liquid supply means and said chamber, a pin centrally located in said chamber with its axis parallel to the longitudinal axis of the flexural member, a frustum-shaped roller supported in the chamber by said pin for orbital movement thereabout and engaging a portion of the inner wall of said chamber, said roller adapted to follow an orbital path about said chamber as a result of said gyratory movement and to engage different portions of said chamber to compress said liquid into a thin arcuate film so as to permit the centrifugal force generated by the gyratory movement of the nozzle to atomize the liquid film.

References Cited by the Examiner UNITED STATES PATENTS LOUIS I. DEMBO, Primary Examiner.

EVERETT W. KIRBY, Examiner. 

3. AN APPARATUS FOR ATOMIZING LIQUID COMPRISING A BASE MEMBER, AN ELONGATED FLEXURAL MEMBER, MEANS CONNECTED TO SAID BASE FOR SUPPORTING SAID FLEXURAL MEMBER, A NOZZLE FORMED AT ONE END OF SAIDF FLEXURAL MEMBER, MEANS FOR SUPPLYING LIQUID TO SAID NOZZLE, A VIBRATOR CONNECTED TO SAID FLEXURAL MEMBER AT THE OTHER END THEREOF, MEANS FOR DRIVING SAID VIBRATOR TO CAUSE A GYRATORY MOVEMENT OF SAID FLEXURAL MEMBER AND NOZZLE, SAID NOZZLE TERMINATING WITH A FRUSTUM-SHAPED CHAMBER, A FEEDER PASSAGE FORMED IN THE NOZZLE AND COMMUNICATING WITH SAID LIQUID SUPPLY MEANS AND SAID CHAMBER, A PIN CENTRALLY LOCATED IN SAID CHAMBER WITH ITS AXIS PARALLEL TO THE LONGITUDINAL AXIS OF THE FLEXURAL MEMBER, A FRUSTUM-SHAPED ROLLER SUPPORTED IN THE CHAMBER BY SAID PIN FOR ORBITAL MOVEMENT THEREABOUT AND ENGAGING A PORTION OF THE INNER WALL OF SAID CHAMBER, SAID ROLLER ADAPTED TO FOLLOW AN ORBITAL PATH ABOUT SAID CHAMBER AS A RESULT OF SAID GYRATORY MOVEMENT AND TO ENGAGE DIFFERENT PORTIONS OF SAID CHAMBER TO COMPRESS SAID LIQUID INTO A THIN ARCUATE FILM SO AS TO PERMIT THE CENTRIFUGAL FORCE GENERATED BY THE GYRATORY MOVEMENT OF THE NOZZLE TO ATOMIZE THE LIQUID FILM. 